Stiffness memory nanohybrid scaffolds generated by indirect 3D printing for biologically responsive soft implants.

Cell and tissue stiffness is an important biomechanical signalling parameter for dynamic biological processes; responsive polymeric materials conferring responsive functionality are therefore appealing for in vivo implants. We have developed thermoresponsive poly(urea-urethane) nanohybrid scaffolds with 'stiffness memory' through a versatile 3D printing-guided thermally induced phase separation (3D-TIPS) technique. 3D-TIPS, a combination of 3D printing with phase separation, allows uniform phase-separation and phase transition of the polymer solution at a large interface of network within the printed sacrificial preform, leading to the creation of full-scale scaffolds with bespoke anatomical complex geometry.